Yorkshire RHS expert talks of Giant Hogweed dangers

Giant Hogweed has been in the news recently after two boys ended up in hospital. But is it on the increase and how do you treat it? Chris Bond reports.

IT sounds like something straight out of Harry Potter, and with its distinctive white flowers it can look quite attractive.

But although Giant Hogweed might seem like a harmless plant it’s actually anything but and in some parts of the UK this toxic and invasive weed is on the increase.

It’s been back in the news after two boys in Bolton were hospitalised with burns injuries after touching the plant, while in Scotland a 10 year-old girl was left with horrible burn marks after picking up a piece of the plant near Loch Lomond.

Both cases have led to calls for warning signs to be put up in areas where the invasive plant is running rampant.

But how common is it and what should people be looking out for? According to the Royal Horticultural Society it can be found in most parts of the UK. Heracleum mantegazzianum - or Giant Hogweed as it’s better known - is particularly common along riverbanks and on wasteland and can even be found in people’s gardens.

The plant, a close relative of cow parsley, has white flowers, thick bristly stems and can grow beyond 16ft (5m) tall.

Ailsa Henderson, one of Yorkshire Wildlife Trust’s living landscape officers, says dealing with the toxic plant is difficult because each plant can produce thousands of seeds.

“These seeds can lie dormant for up to 10 years and then they just pop out which makes it tricky to deal with,” she says.

The Trust leads Yorkshire’s invasive species forum and Giant Hogweed is one of the plants they are trying to help control. “We’ve been tackling this for several years and we’re training up volunteers to help us identify where it’s popping up,” she says.

They have created a map, which can be viewed online, that shows where some of the local hotspots are, such as along the River Aire in Leeds. “We want people to know where Giant Hogweed is in their area and this is a good way of doing that.”

In those places where it’s well established it’s also on the rise, as Paul Cook, curator at RHS Garden Harlow Carr in Harrogate, points out.

“You tend to find it in less accessible places,” he says. “In some parts of the county it’s increasing and in others, where it’s been controlled, it’s going down.”

It’s attractive appearance can lull unsuspecting people who stumble across it into a false sense of security.

“It’s very distinctive but a lot of people have forgotten just how horrible it can be,” says Paul.

Those who encounter Giant Hogweed certainly don’t forget it in a hurry. “When the sap or juice from the stem comes into contact with the skin it can cause intense irritation, particularly in the sunny weather.

“It doesn’t last very long but it can feel like you’re skin is being burned.”

Giant Hogweed actually originated in the mountains of Central Asia and was introduced into Britain by Victorian plant collectors.

It contains toxic components in the leaves, stems, seeds and flowers which can be transferred to skin by touch. These don’t cause burning alone - but instead make skin hyper sensitive to sunlight, which can then cause rashes, burns and even severe blistering.

The effects don’t necessarily start away, sometimes taking 24 hours to appear and the advice for anyone who touches Giant Hogweed is to wash the area of skin with soap and water, and keep it covered.

With the school summer holidays about to start Paul says it’s a timely reminder for adults and children to be on the lookout.

“We’re not one of the worst counties for Giant Hogweed, but there are still odd patches of it here and it’s a good time to raise awareness and highlight what an irritant it can be.”